Releasable screen attachment for hammer mills



April 6, 1937. A. 1 HZLE JR l 2,076,025

RELEASABLE SCREEN ATTACHMENT FOR HAMMER MILLS Filed Jan. 14, 1935 2 Sheets-Sheet l April 6, 1937- A. J. HAZLE, .1R 2,076,025

RELEASABLE SCREN ATTACHMENT FOR HAMMER MILLS Filed Jan. 14, 1935 2 Sheets-Sheet 2 fu l@ N Q Q m' `v I if lili a l il w M s o g l m il N Patented Apr. 6,' 1937 yUNITED STATE-s PATENT OFFICE vassassinati". senaat; grscmmnr ron Albert J. male, Jr., chime, nl., mmm to ghi. glimp Co., Chicago, Ill., a corpora tion of Application January 14, 1935, Serial No. 1,816 2 Claims. ((\li.,8311) This invention relates to hammer mills and arm I9A which extends downwardly along the concerns itself with novel means for supporting side wall ofthe casing as shown in Figures 3 a screen whereby the same may be quickly reand 4. g y f leased and removed and a new one or one of A rod 20 which is pivoted to a bracket 2l as different mesh may be quickly and readily inindicated at 29a extends through a. bifurcation 5 sertedl 22in the lower end of the arm I9 and is pro- Y The invention comprises the novel structure vided with a threaded nut 23 at its end that and combination of parts hereinafter described engages the arm I9 when the chains are in their and more particularly pointed out inthe ap. applied positions. When the nut 23 is threaded 1o pended claims. v against the arm I9 to swing the `saine in an 1o In the accompanying drawings which illusanti-clockwise direction as viewed in Figure 1, trate a preferred form of this invention and in the ,shaft I8 will be rocked to .move the arms which similar reference numerals refer` to simi- Il toward the arcuate bars II. At the same lar features in the different views: time, .the links I5 will be 'elevatedand forced Figure 1 is a sectional view through a hamin the direction of the screen. When the nut 23 15 mer `mill involving this invention. is threaded in a direction a'way from the arm Figure 2 is a sectional view taken at right I9, the pressure exerted against the Chains will angles tol the plane of' Figure 1. of course be released. When the nut .23 is sum- Figure 3 is an enlarged sectional view taken Cientlyunthree-ded; the rod 20 may swingdown- 2 with parts in elevation. l, Vwholly release the same, so that the arm I9 rnay Figure 4 is anA enlarged fragmentary elevabe manually swung to release the chains as much tional view of the left hand end of Figure 3. as desired.

' In the drawings there is shown a hammer mill The casing is provided with a curvedztop wall comprising a casing having side walls I and 2, 24 that extends adjacent the forward ends of 25 a front wall 3 and a rear curved wall 4 which y ,the bars II. The front wall is forwardly'oifset rests upon a supporting base 5 which supports fromthe top wall 24. A curvedA cover plate 25 the bearings 6 for the rotor shaft 1 upon which bridges the space between thefront wall 3 and a rotor 8 is secured that carries swinging beaters the top wall 24. The inner edge of the cover 9 that cooperate with a grind surface for grindplate` 25 extends inwardly between the lower 30 ing or'crushing material as is well known in the edge of the ipp wall 24 and the upper front 'ends art. A portion of this grinding surface is in the '0f the bars II. A ange 25 upon the interior form of a screen I0 and the invention herein is side of the cover pla 25 ts against the upper directed to the means for releasably supporting `end of the screen. e cover plate 25 has a lower the screen. L l outwardly offset portion-2l forming a shoulder 35 Upon the side walls I and 2 of the casing are 28 that rests upon the top of the front wall. secured arcuate bars Il that are substantially The offset portion 21 engages the outer surface semi-circular in extent. The screen IU ts of the front wall which is provided with threadagainst thebars II and is clamped thereagainst ed pegs 29 that extend through such offset por- 40 by means of a pair of flexible membersin the tion. Wing nuts 30 threaded upon the pegs 29 4o form of chains l2, Ity wi11 be noted that these hold the coverlplate 25111 place. The cover plate chains are in opposed relation to the arcuate 25 iS DIOVided With a handle 3l whereby the bars Il and that the rear ends thereof are ats ame may be removed or replaced. gIf desirable tached to arms I3 (only one of which is shown). the section 32 of the top wall 24 adjacent the The arms I3 are secured upon a shaft I4 jourcover plate including the'corrugated surface 45 nailed in the side walls of the case adjacent the thereon may also be made removable and suprear upper end of the screen. l pliedwith a finger piece 33. The removable The forward ends of the chains I2 are at" cover 25 is provided for the purpose of removtached to the ends of links I5 which are pivoted ing a screen and inserting another as'will later upon a rod I6 carried by crank arms Il rigidly` more fully-appear. 50 attached to a shaft I8 journalled in the side It is .desired to point out that the yrocking of walls of the casing. The arms I'I and links I5 the shaft I8 in an anti-clockwise direction to form toggles. The shaft I8 extends through the clamp the chains I2 against the screen swings side wall I`of the casing, and upon the extended the arms I3 and links I5 toward the screen to end of said shaft there is secured a tongue or firmly bind the chains against such screen. It 55 substantially upon the line III-III of Figure 1 wardly through the bifurcation inthe arm I9 and 20- should also be noted that the operating and releasing means for the chains will always be effective for tightly clamping the chains against the screen no matter if such chains shouldwear 5 or stretch a certain amount. 'I'his is due to the fact that the crank arms H'can be swung -up'- wardly further if stretching in the chains occurs. Of course, in the present construction as shown, the arms I1 can only be swung upwardly in an operative direction until they strike the screen. There is however suflicient clearance in the illustrated construction for practical purposes. v

In the use of such a machine, it is frequently desirable to change the screen, according to the required flneness of the grind. Screens of different mesh are usually held in stock for such a purpose. When it is desired to change the screen, it is only necessary 'to remove the cover plate 25 and unthread the nut 23 sumciently to allow the shaft I8 to rock in a clock-wise direction. In 'this mannen-it is possible to drop the chains insufficiently to release the screen so that it can be easily withdrawn through the opening provided by the removed cover. 'Ihen a new or different screen may be easily inserted since there will be such a space between the arcuate bars ll and the released chains that no trouble will be encountered in inserting a new or different screen.

From the foregoing, it will be apparent that a novel and efl'ective mechanism has been invented for clamping and releasing screens in hammer mills or the like that takes up wear or stretching of the clamping members, and that greatly facilitates the removal orVA replacementwofthe screen.

I am aware that many changes may be madey ing, a pair of arcuate bars attached to said casing in parallel relation, a screen fltting against said bars, a pair of chains, means for movably anchoring said chains adjacent the rear ends of said bars, a shaft adjacent the forward ends of said bars, connections between said shaft and chains, an arm upon'sad shaft having a bifurca tion, a rod pivotally connected to said casing and extending through said bifurcation and a nut threaded on said rod and engaging said arm for rocking said shaft.

2. In a machine of the class described, a casing having side walls, an arcuate bar secured to the interior of each side wall, a screen tting against said bars, flexible members for clamping said screen against said bars, a pair oi.'y swingable arms pivoted to said casing and extending upwardly at an angle toward said screen and attached respectively to the rear ends of said flexible members, a rockable shaft, arms upon said shaft, a rod carried by saidl arms, upwardly extending links connecting said rodv with -the front ends ofsaid flexible members and means for operating said shaft.-

ALBERT J. HAZLE, Jn. 

